Method for producing a packaging means and packaging means made of flexible material

ABSTRACT

A method for producing a package made of a flexible material, in which a single flexible material web is folded longitudinally, and superposed layers of the folded material web are firmly bonded to one another. At least one section of the material web is constructed as a tubular piece, and individual gusset edges of the material web are at least partly cut. Tubular pieces of a predetermined length are cut from the material web, in the area of at least one opening of the tubular piece. The outer layers are turned over, and layers of the material located therebetween are shortened. A sealing element is applied to the ends of the shortened layers and brought in contact with one of the outer layers. The shortened ends are closed after re-turning the outer layers, and fixed to a respective outer layer. Predefined regions of superposed layers of the tubular piece are then firmly bonded to one another.

BACKGROUND OF THE INVENTION

The invention relates to method for producing a packaging means made of a flexible material, in particular for producing a side gusset bag made of plastic film. Furthermore, the invention relates to a packaging means made of a flexible material, in particular side gusset bags made of plastic film, comprising a front wall and a rear wall between which side gussets extending over sections of their lateral areas are disposed, said side gussets being designed to be shortened in the upper region of the packaging means, the packaging means having a gusset-free head region between the front and rear wall.

It is known to produce a packaging means made of a flexible material, for example, a side gusset bag made of a plastic film, by arranging two material webs congruently with respect to one another and positioning predefined functional elements between said material webs and optionally bringing into contact with the material webs. Subsequently, predefined regions of the material webs are joined to one another and the finished packaging means is separated as sections from the joined material webs. The known methods are very complex and very expensive to implement.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a method for producing a packaging means which is comparatively easy to implement and at the same time allows the packaging means to be produced at a favourable cost.

This problem is solved by a method according to the invention for producing a packaging means made of a flexible material, in particular for producing a side gusset bag made of plastic film, in which a single flexible material web is folded in the longitudinal direction, superposed layers of the folded material web are firmly bonded to one another and at least one section of the material web is constructed as a tubular piece, individual gusset edges of the material web constructed as a tubular piece are at least partly cut, and then tubular pieces of a predetermined length are cut from the material web, in the area of at least one opening of the tubular piece its outer layers are turned over and layers of the material located therebetween are shortened, a sealing element is applied to the ends of the shortened layers and brought in contact with one of the outer layers, the shortened ends are closed after re-turning the outer layers and fixed to a respective outer layer and predefined regions of superposed layers of the tubular piece are firmly bonded to one another.

The method according to the invention can advantageously be used to produce a packaging means from a material web which allows the packaging means to be produced simply and therefore cost-effectively by means of the process features according to the invention.

According to a further development of the invention, it is particularly advantageously provided that the material web is folded in such a manner that its longitudinal sides are superposed in one of the lateral regions of the folded material web. As a result of the advantageous folding of the material web and the superposition of the longitudinal sides in particular in the area of a side gusset, the entire width of the material can advantageously be used.

After folding the material web, the superposed longitudinal sides are firmly bonded to one another. The firm bonding creates a firm or permanent and therefore advantageously secure contact between the superposed longitudinal sides. The firm bonding can be effected, for example, by a specific supply of heat along pre-determined sections of the superposed longitudinal sides of the folded material web, wherein predetermined sections of the material web can be formed into a tubular piece.

In a further development of the method according to the invention, the gusset edges in the lateral regions of the material web are firmly bonded to one another jointly with the superposed longitudinal sides over a predefined section of their extension. The additional firm bonding of all the gusset edges of the material web advantageously imparts more stability to the tubular piece produced, which is why further processing is simplified and the packaging means filled with the products has improved dimensional stability.

In a further processing step according to the invention, certain regions of the material web are cut away along the firmly bonded gusset edges. The cuts made on both sides of the material web which is almost equivalent to a trimming of edge regions advantageously opens predetermined sections of the lateral regions of the material web. In particular, it is possible for the cutting tools to be brought in contact with the gusset edges, for example, only at predetermined intervals so that interrupted cutting profiles are formed along the gusset edges.

Alternatively, it is provided according to another further development of the method according to the invention that predetermined sections of the gusset edges are cut open. Cutting open the gusset edges has the advantage that no material clippings are formed at the gusset edges and thus the width of the folded web is advantageously preserved.

The tubular pieces are separated from the material web in such a manner that the opened lateral regions are embodied as sections of different length at a respective end of each tubular piece. The individual formation of the opened lateral regions at the respective end of each tubular piece is effected by trimming the tubular pieces and allows an advantageous configuration of the tubular pieces with regard to their further processing so that the completion of the packaging means, in particular the firm bonding at the ends of the lateral regions can advantageously be carried out in a simplified manner. It is naturally possible to vary or adapt the length of the ends of a tubular piece opened in the lateral regions during production.

The separated tubular piece is turned in its horizontal position through about 90° for further processing. The turning of each tubular piece whilst maintaining the same direction of transport advantageously provides the possibility for carrying out further processing steps on both sides of the conveyor belt. This results in further simplified production or a shortened production process for the packaging means. After separating the tubular pieces from the material web, it is also possible to transport the individual tubular pieces further whilst keeping the alignment unchanged at an angle of about 90 degrees to the original direction of motion.

At the ends of each tubular piece, the outer layers are turned over in the area of both tubular openings and the layers of the material located therebetween are shortened. The shortening of the side gussets in the upper region has the advantage that a gusset-free head region is created between the outer layers forming the front or rear wall of the packaging means. The side gussets can also be shortened by a predetermined amount in the lower area of the tubular piece which is constructed as the bottom area of the packaging means, whereby a firm bonding of the tubular opening can advantageously be achieved in the bottom region over the entire width of the outer layers. At the same time, increased stability of the packaging means is ensured in the bottom region. It is not necessary to use costly stamping tools to produce an opening in the lower region of the side gussets by which means the otherwise usual bonding of the lateral regions is accomplished in the bottom region of the packaging means.

According to another further development of the method according to the invention, a sealing element is applied in each case to the individual upper ends of the shortened layers. By using two separate sealing elements, a smaller quantity of sealing element which seals the side gussets is required to produce a packaging means. In addition, as a result of the shortened sealing elements which are welded to the shortened layers or side gussets and one of the outer layers, corresponding heat must act on a reduced area so that an energy saving can advantageously be made at the same time.

A re-closure member is inserted between the outer layers of the tubular piece above the sealing element and is then bonded firmly to its inner side. The re-closure member is inserted in particular in the head region of the packaging means free from side gussets and can advantageously be brought into contact with the heat-sensitive inner side of the outer layers of the packaging means over its entire width. The outer layers can be heated by a specific supply of heat in the area of the re-closure member whereby the inner sides of the outer layers fuse with the re-closure element and a permanent firm bonding can be achieved.

After -re-turning the outer layers, the opened lateral regions of the superposed layers are firmly bonded to one another in the area of the tubular openings and then the outer layers are firmly bonded to at least one of the tubular openings in the edge region. In order to advantageously first fix the side gussets between the outer layers of the tubular piece, the opened lateral regions are preferably first welded together and then the tubular opening in the bottom region of each tubular piece is sealed in a leak-free manner. For example, it is possible that each tubular opening in the bottom region of a respective tubular piece is sealed by means of two parallel bonding lines. As a result of the strengthened configuration of the double-sealed bottom region which can receive a higher loading, packaging means having larger dimensions can advantageously be produced.

In order to form a contact area in the bottom region of each packaging means, projecting material is turned over and adhesively bonded to one of the outer layers. The projecting or lengthened material can advantageously be used to form a flat contact area in the bottom region of the packaging means so that the individual packaging means can be stored in a standing position and among other things, it is possible to achieve a higher packing density during transport or during storage of the stacked packaging means. The lengthened outer layers of the tubular piece can be used as projecting material, for example, whereby the attachment of a separate material section can advantageously be dispensed with.

In the case of a packaging means made of flexible material, in particular side gusset bags made of plastic film, comprising a front wall and a rear wall between which side gussets extending over sections of their side regions are arranged, said gussets being embodied as shortened in the upper region of the packaging means, which can be produced in particular by a method according to claims 1 to 13. it is provided according to the invention that each upper end of the side gussets is closed by a separate sealing element which fixes the respective side gusset end at precisely one of the packaging-means walls. Using two separate sealing elements having approximately the width of a side gusset makes it possible to achieve easy and advantageous filling or removal of goods to be enclosed or enclosed by the packaging means. No sealing element is provided in the area between the side gussets so that the original flexibility of the material and thus of the packaging-means wall is preserved. Consequently, the region around the sealing elements can be deformed relatively easily during filling, for example, thus ensuring advantageous handling. Furthermore, a respective side gusset can be fixed either on the rear wall or on the front wall of the packaging means by means of the sealing element.

According to a first further development of the invention, it is provided that each sealing element is firmly bonded to a respectively allocated side gusset and a respective packaging-means wall. The adhesive bonding advantageously creates a firm bond between the sealing elements, the respective side gussets and a respective packaging-means wall, whereby individual parts or components of the packaging means can be permanently and at the same time securely joined together. Preferably the parts or components are welded together so that the materials of the different parts form a non-detachable bond with one another. It is naturally also possible that other methods, for example, gluing can be used for the bonding.

It is particularly advantageous if at least one free end of each sealing element ends between and at the same time at a distance from the seam edges of at least side seam joining at least the front and rear wall to one another. The shortened construction of the sealing elements in the area of the side seams of the packaging means according to the invention ensures an improved seal of the side seams. The firm bonding of the layers to be joined to one another is thus no longer completely broken, thereby additionally improving the visual properties of the packaging means according to the invention. The sealing elements each end between and at a distance from seam edges of a respective side seam, the sealing elements preferably being stopped at half or the centre of the side seam.

Each sealing element is a material strip which can be brought into contact with the upper ends of the side gusset and locks this firmly to one of the packaging-means walls. The use of a material strip in conjunction with the shortened configuration has the advantage that a PE/PET composite film, for example, can be used as the material strip. The composite film can be made from a plurality of film layers having different properties, at least one film layer of the composite film having an advantageously low melting point. When heat is appropriately supplied in the region of the sealing element, merely this film layer forms a firm bond with the relevant side gusset and the corresponding packaging-means wall.

In order to ensure the quality of the goods enclosed by the packaging means after a first opening of said packaging means, a re-closure member is arranged in the head region above the sealing element. The product can advantageously be removed from the packaging means in a portioned manner using this re-closure member. At the same time, the re-closure member creates a flavour seal which, for example, slows premature drying-out of the enclosed products or goods or should reduce the absorption of moisture.

The free ends of the re-closure member preferably end in the side seams and at the same time at a distance from the outer edges of the side seams of the packaging means so that predetermined regions of the side seams are not interrupted. The side seams which are embodied as continuous at least in part regions effect an increased sealing of the packaging means according to the invention and therefore a permanently uniform quality of the product contained therein.

The re-closure member is formed from interlocking elements which correspond to one another, allowing a re-closable sealing of the packaging means. The interlocking elements provide an advantageously simple configuration of a re-closure member, the interlocking elements intermeshing with one another in such a manner as to ensure an almost airtight sealing or closure of the packaging means. A first interlocking element can, for example, have a groove in which a hook-shaped web of the second interlocking element engages over the length of its extension. It is likewise possible to construct the re-closure element, for example, as two adhesive strips each assigned to the bag walls.

According to a further development of the invention, it is provided that the individual interlocking members are assigned to a respective packaging-means wall. The interlocking elements which correspond to one another are arranged in particular in the side-gusset-free head region of the packaging means on the inner sides of the front or rear wall. A firm bond is preferably created between the front or rear wall and the respective interlocking elements. The firm bonding holds the interlocking elements firmly and permanently on the inner sides of the packaging-means walls.

Each side gusset is constructed as shortened in the head region and in a bottom region. The configuration of a shortened side gusset at both ends has the advantage that in particular, in addition to using a re-closure member in the head region, the shortened side gusset in the bottom region of the packaging means allows an advantageously simple joining of the front and rear wall. As a result of the shortened side gussets in the bottom region, it is not necessary to provide the individual side gussets with an opening in the region of the bottom welded seam in order to facilitate the necessary joining of the front and rear wall.

In an advantageous embodiment it is provided that the front wall and the rear wall are continuously firmly bonded to one another in the bottom region. The continuous firm bonding of the front and rear wall in the bottom region of the packaging means advantageously ensures improved formation of the bottom after filling with the products to be enclosed with the packaging means. In particular, in the case of packaging means which is to be stored or transported vertically for example, the continuously bonded front and rear wall creates an improved contact area. The inner sides of the front and rear wall of the packaging means can preferably be welded to one another by specifically supplying heat in an edge region of the bottom. Other joining methods, such as gluing for example, can also be used among other things to join the regions of the packaging means to be brought into contact with one another.

According to a further development of the invention it is provided that the bottom region of the packaging means has two firm-bonding lines running parallel to one another. The formation of two firm-bonding lines in the bottom region of the packaging means allows the formation of a bottom fold by which means an advantageously flat contact area of the packaging means can be produced. The bottom fold can be formed, for example, from the lengthened front and rear wall which project beyond the side gusset in the bottom region. The section forming the bottom fold can optionally be turned over and glued to the outer side of one of the wall of the bottom region of the packaging means.

The bottom region has at least one diagonal bonding line which firmly bonds regions of a respective side gusset to a respectively relevant packaging-means wall. The diagonal bonding lines which can be formed in particular as welded seams join the side gussets to the packaging-means walls and ensure an increased stability in the bottom region of the packaging means and a strengthened contact area resulting therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the method according to the invention and an exemplary embodiment of the packaging means according to the invention from which further inventive features are obtained are shown in the drawings. In the figures:

FIG. 1: is a schematic view showing how a material web is folded;

FIG. 2: is a sectional view of the folded material web;

FIG. 2 b: is a schematic plan view of the folded material web with a firmly bonded section;

FIG. 2 c: is a section of a tubular piece separated from the material web;

FIG. 3 a: is a view of the tubular piece turned through 90 degrees in the plane for further processing;

FIG. 3 b: is a schematic view showing how the outer layers of the tubular piece are turned over;

FIG. 3 c: is a plan view of the tubular piece with its shortened side gussets;

FIG. 4 a: is a schematic view showing how the outer layers are turned back in the bottom region and applied to the upper ends of the side gusset sealing elements;

FIG. 4 b: is a view of the tubular piece with joined side end sections in the bottom region and an inserted re-closure member in the side-gusset-free head region of the tubular piece;

FIG. 4 c: is a schematic view showing how the sealing elements and the re-closure member in the head region are firmly bonded to the tubular piece and core seams are produced in the bottom region;

FIG. 4 d: is a schematic view of the packaging means with closed bottom and joined side end sections in the head region, and

FIG. 5: is a perspective view of a [packaging means] according to the invention with shortened side gussets between the packaging-means walls.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In FIG. 1 reference numeral 1 denotes a material web made of a flexible material which can be unrolled from a roll 2, for example. In this case, the material web 1 is folded in its longitudinal direction, forming several superposed layers 3 of which two inner layers in each case are embodied as side gussets. The folded material web 1 is constructed similarly to a tube, the longitudinal sides 5, 6 of the material web 1 being superposed in the lateral region 4.

FIG. 2 shows a section through the folded material web 1 and is intended to illustrate the structure. FIG. 2 shows the various layers 3 of the folded material web 1, the material web 1 being folded in such a manner that the longitudinal sides 5, 6 and the gusset edges 7, 8, 9 form the lateral edges of the folded material web. FIG. 2 further illustrates that the folded material web 1 has two outer layers 10, 11 and in the lateral regions 4, 12, layers 13, 14 which are located therebetween in each case and are embodied as side gussets.

FIG. 2 b shows how the folded material web 1 in the lateral regions, in particular the longitudinal sides 5, 6 and the gusset edges 7, 8, 9 are firmly bonded to one another over a predetermined section of their extension. The material web is then trimmed at the edges of its lateral regions so that the layers 10 and 13 or the layers 11 and 14 in the lateral regions are separated from one another and therefore open in the partial sections 15, 16 of the folded material web 1 which are not firmly bonded to one another in the lateral regions 4, 12.

FIG. 2 c shows a tubular piece 16 separated from the material web 1 which is supplied for further processing.

As illustrated in FIG. 3 a, each tubular piece 17 is turned through 90 degrees in the horizontal plane before further processing so that in particular a head region 18 and a bottom region 19 are accessible for further processing.

FIG. 3 b shows how the outer layers 10, 11 are turned back in the head region 18 and also in the bottom region 19 and therefore the inner layers 13, 14 protrude.

FIG. 3 c is intended to illustrate how the protruding inner layers 13, 14 are shortened in the head region 18 and in the bottom region 19. In this case, as shown in FIG. 3 c, the inner layers 13, 14 can be shortened to different lengths in the regions 18, 19.

After the shortening, the outer layers 10, 11 are re-turned in the bottom region, wherein, as shown in FIG. 4 a, only one outer layer 11 is turned back in the head region and a sealing element 20 is applied to the upper ends of the inner layers 13, 14 which are also designated as side gussets.

The schematic side and plan view in FIG. 4 b shows how the returned layers 10, 11 in the bottom region of the tubular piece 17 are firmly bonded to the respective inner layers 13, 14 in the lateral regions 4, 12. In the head region a re-closure element 21 is inserted above the shortened inner layers 13, 14 between the outer layers 10, 11, which re-closure element can be formed, for example, from interlocking elements which corresponding to one another.

FIG. 4 c is a schematic view which is intended to illustrate how a transverse firm bonding 22, 23 embodied as a welded seam is made in the bottom region 19 between the outer layer 10 and the inner layer 13 or between the outer layer 11 and the inner layer 14 and permanently joins the corresponding layers one to the other. In the head region 18, after folding back the layer 10, the sealing elements 20 are welded to the inner layers 13, 14 and the outer layer 11, the upper end of the inner layers 13, 14 being sealed by the respective sealing element 20. At the same time, the re-closure element 21 is firmly bonded to the inner sides of the outer layers 10, 11.

FIG. 4 d shows a schematic diagram of the finished packaging means in which the tubular opening 24 in the bottom region of the tubular piece 17 is sealed by firm bonding of the outer layers 10, 11 in the last processing step of the method. At the same time, with the sealing of the outer layers 10, 11, the inner layers 13, 14 are joined to one of the respective outer layers 10, 11 and the inner layers 13, 14 formed as side gussets are sealed at the lower end in the bottom region 19. In the head region 18 of the tubular piece 17, the respective upper lateral regions 4, 12 are firmly bonded to one another so that continuously sealed lateral regions 4, 12 of the packaging means are obtained and the space located between the outer layers 10, 11 forms a chamber delimited from the surroundings.

FIG. 5 shows a packaging means according to the invention comprising a front wall 25 and a rear wall 26 which are made of a flexible material, in particular a plastic film. Side gussets 28, 29 extend between the front wall 25 and the rear wall 26 in a respective lateral region 27, these gussets being embodied as shortened in a head region 30 and in a bottom region 31 in each case. The upper ends of a respective side gusset 28, 28 are each sealed with a sealing element 32 and at the same time fixed to the rear wall 26. The side gussets 28, 29 are in each case firmly bonded to the front and rear wall in the edge regions 33 so that a firm and at the same time a permanent join is produced between the individual components of the packaging means. A re-closure member 34 is arranged in the side-gusset-free head region 30 of the packaging means, which member protects the product inside the packaging means from the prevailing ambient conditions such as moisture in the air or dust, for example, after the packaging means has been opened for the first time and the product enclosed by said packaging means has been removed in portions. The re-closure member 34 which can be formed in particular from corresponding interlocking elements, forms a firm bond with the inner side of the front wall 25 and the rear wall 26. In order to form a smooth contact area 35 in the bottom region 31 of the packaging means, the front wall 25 and the rear wall 26 are constructed as lengthened and are brought into contact by means of two non-visible firm bonding lines which run parallel to one another. The bottom fold 36 thereby formed is turned over and glued to the bottom region 31 of a respective packaging means. 

1. A method for producing a packaging means made of a flexible material, comprising the following steps: folding a single flexible material web in a longitudinal direction; bonding superposed layers of the folded material web to one another, wherein at least one section of the material web is tubular in structure; partially cutting individual gusset edges of the material web, cutting a tubular piece of a predetermined length from the material web; turning over outer layers in the area of at least one opening of the tubular piece; shortening layers of the material located between the outer layers; applying a sealing element to ends of the shortened layers; bringing the shortened layers in contact with one of the outer layers; turning the outer layers back to their starting position; fixing the shortened layers to a respective outer layer; and bonding predefined regions of superposed layers of the tubular piece to one another.
 2. The method according to claim 1, wherein the material web is folded so that its longitudinal sides are superposed in a lateral region of the folded material web.
 3. The method according to claim 2, wherein the superposed longitudinal sides of the folded material web are firmly bonded to one another during said step of bonding.
 4. The method according to claim 3, wherein the gusset edges in the lateral region of the material web are bonded to one another jointly with the superposed longitudinal sides over a predefined section of their extension.
 5. The method according to claim 4, wherein the step of partial cutting takes place along the bonded gusset edges.
 6. The method according to claim 1, wherein the step of cutting includes cutting open the gusset edges.
 7. The method according to claim 1, wherein during the step of cutting, the tubular piece is separated from the material web so that opened lateral regions are embodied as sections of different length from each other at respective ends of each tubular piece.
 8. The method according to claim 7, further comprising turning the separated tubular piece horizontally through about 90° for further processing.
 9. The method according to claim 1, wherein the outer layers are turned over at both tubular openings and the layers of material located therebetween are shortened.
 10. The method according to claim 1, wherein a separate sealing element is applied to each of the individual upper ends of the shortened layers.
 11. The method according claim 1, further comprising inserting a re-closure member between the outer layers of the tubular piece above the sealing element and bonding the re-closure element to an inner side of the outer layers.
 12. The method according to claim 4, wherein after the step of turning the outer layers back to their original position, the opened lateral regions of the superposed layers are firmly bonded to one another in an area of the tubular openings and then the outer layers at at least one of the tubular openings are firmly bonded to one another in an edge region.
 13. The method according to claim 1, wherein projecting material in a bottom region of the tubular piece is turned over and adhesively bonded to one of the outer layers.
 14. A package made of flexible material, comprising: a front wall and a rear wall between which side gussets extending over sections of their side regions are arranged, said gussets being shortened in an upper region of the package, wherein the package has a gusset-free head region between the front and rear wall, wherein an upper end of each side gusset is closed by a separate sealing element, which fixes the respective side gusset end at precisely one of the package walls.
 15. The package according to claim 14, wherein each sealing element is bonded to a respectively allocated side gusset and a respective packaging-means wall.
 16. The package according to claim 14, wherein at least one free end of each sealing element ends between and at a distance from edges of at least one side seam joining the front and rear wall to one another.
 17. The package according to claim 14, wherein each sealing element is a material strip.
 18. The package according to claim 14, further comprising a re-closure member arranged in the head region and above the sealing element.
 19. The package according to claim 18, wherein free ends of the re-closure member each end in the side seams and at a distance from outer edges of the side seams.
 20. The package according to claim 18, wherein the re-closure member is formed from interlocking members which correspond to one another.
 21. The package according to claim 20, wherein the individual interlocking members are assigned to a respective package wall.
 22. The package according to claim 14, wherein each side gusset is shortened an area near the head region and in a bottom region.
 23. The package according to claim 14, wherein the front wall and the rear wall are continuously firmly bonded to one another in a bottom region.
 24. The package according to claim 23, wherein the bottom region has two bonding lines running parallel to one another.
 25. The package according to claim 23, wherein the bottom region has at least one diagonal bonding line which bonds regions of a respective side gusset to a respective package wall. 